public partial class Form4 : Form{  private Bitmap myBitmap;  public Form4()  {   InitializeComponent();   DataTable dt = new DataTable();   DataColumn dc1 = new DataColumn("Name", typeof(System.String));   DataColumn dc2 = new DataColumn("Age", typeof(System.String));   dt.Columns.Add(dc1);   dt.Columns.Add(dc2);   for (int i = 0; i < 20; i++)   {    DataRow row = dt.NewRow();    row["Name"] = i.ToString();    row["Age"] = i.ToString();    dt.Rows.Add(row);   }   comboBox1.DataSource = dt;  }  private void comboBox1_Format(object sender, ListControlConvertEventArgs e)  {   DataRowView myDataRowView = (DataRowView)(e.ListItem);   e.Value = string.Format("{0}-{1}-{2}", myDataRowView["Name"], myDataRowView["Name"], myDataRowView["Name"]);  }}